ASTM_D_1917_-_03_2012.pdf

Designation:D191703(Reapproved 2012)Standard Test Methods forRubber PropertyShrinkage of Raw and Compounded Hot-Polymerized Styrene-Butadiene Rubber(SBR)1This standard is issued under the fixed designation D1917;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the Department of Defense.1.Scope1.1 These test methods cover the determination of millshrinkage of hot-polymerized styrene-butadiene rubbers(SBR)and their compounds.1.2 The values stated in SI units are to be regarded as thestandard.The values in parentheses are for information only.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.2.Referenced Documents2.1 ASTM Standards:2D3182 Practice for RubberMaterials,Equipment,and Pro-cedures for Mixing Standard Compounds and PreparingStandard Vulcanized SheetsD3896 Practice for Rubber From Synthetic SourcesSamplingD4483 Practice for Evaluating Precision for Test MethodStandards in the Rubber and Carbon Black ManufacturingIndustriesE145 Specification for Gravity-Convection and Forced-Ventilation Ovens3.Summary of Test Methods3.1 A specimen of raw or compounded rubber is preparedon a standard laboratory mill,its dimensions are measured orcontrolled by a cutting technique,it is heat aged in a circulatingoven at 100C,cooled at room temperature,and the dimen-sions are again measured.The linear percent shrinkage of thespecimen is calculated.3.2 The following test methods are given:3.2.1 Test Method AFor raw SBR which is particularlyapplicable to rubbers having shrinkage below 25%,such ascross-linked types.3.2.2 Test Method BFor compounded SBR.4.Significance and Use4.1 The shrinkage of SBR rubbers and their compoundsafter processing is of importance in many applications.Thisproperty can also be used for control,specifications,andfabrication purposes.5.Apparatus5.1 MillA standard laboratory mill as described in Prac-tice D3182.5.2 Laboratory Oven,having internal horizontal dimensionsin excess of 300 by 480 mm(12 by 19 in.)and conforming tothe requirements for Type II,Grade B ovens given in Specifi-cation E145.5.3 Mill Knife.5.4 Cutting Tools:5.4.1 Atool having two parallel blades spaced about 20 mm(0.8 in.)apart.Two standard mill knives bolted together,properly spaced,may be used.5.4.2 A150 mm long by 100 mm wide(6.0 by 4.0 in.)metaltemplate approximately 1 mm(0.04 in.)thick,equipped with ahandle,and having its longitudinal dimension curved to fit thecontour of the mill roll,may also be used.It is especiallysuitable for raw rubbers that are disjunctive or form a poorsheet.A mill knife is used for cutting the rubber.5.5 Smooth Sheet,of TFE-fluorocarbon,metal,or glass,having dimensions to accommodate the specimen.5.6 Linear Scale,500 mm(20 in.)long,graduated in 1.0mm(0.05 in.).5.7 Dusting powder,for example talc or soapstone.1These test methods are under the jurisdiction of ASTM Committee D11 onRubber and are the direct responsibility of Subcommittee D11.12 on ProcessabilityTests.Current edition approved May 1,2012.Published May 2012.Originallyapproved in 1962.Last previous edition approved in 2007 as D1917 03(2007).DOI:10.1520/D1917-03R12.2For referenced ASTM standards,visit the ASTM website,www.astm.org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 6.Sampling6.1 Take samples in accordance with Practice D3896.NOTE1Make sure the sample is talc-free.7.Test Specimens7.1 Standard SpecimensThe standard specimen is a stripcut with a double-bladed knife.Three specimens are cut,one inthe center,and two,each halfway between the center and theedge of the banded material.7.2 Template SpecimensAn alternative method is the useof a template.When the template is used,only one specimen iscut exactly around the edges of the template from the center ofthe material banded on the mill.NOTE2These two types of specimens will not necessarily giveidentical results.Results obtained on one type of specimen should not becompared with those obtained using the other.TEST METHOD ARAW RUBBER8.Procedure8.1 With the mill rolls maintained at 50 6 5C(122 6 9F)and roll separation of 0.20 6 0.05 mm(0.008 6 0.002 in.),pass 200 g of rubber twice without banding.8.2 Adjust the roll separation to 0.6 6 0.1 mm(0.024 60.004 in.),band the rubber on the slow(front)roll,and millexactly 10 min.Make three-quarter cuts